I was changing the belts on my 1990 c-4. When tightening the 3 10mm(i think) nuts on the rear pulley, I over tightened and broke off 1 stud flush with the outer face of the pulley. The car seems to run fine with the two nuts holding the pulley.So, since these studs are part of the fan, can the stud be removed with an easy out, and replaced? Or would it have to be drilled out and replaced? New threads tapped? Or helicoil? Also, what do you think about running the car as is? Really don't want to replace the fan if this can be fixed.
Thanks,
Steven

 

This happened to me the other day, the studs are screwed into the fan hub hearing, not part of the fan. I just pulled the pulleys off to expose the face of the fan, sprayed some wd40 in around the stud and unscrewed it. I replaced all 3 of mine with a bolt. Think they were m6x30

 

Thanks, just what I needed to know. Since mine was broken off flush, I will probably have to use an easy out to get the stud out. But, glad that it unscrews.
Thanks

 

Maybe no easy out necessary. Since it broke off in front of the pulley, when I remove the pulley, there may be enough to grab.
Thanks again

 

Exactly! Just make sure you really lubricate the stud before trying! Glad I could help!

 

If it does't come out easily, use a Dremel and cut a slot across the screw head. Then just use a flat blade screwdriver to back it out.

 

Once you have the fan out, the backside of that stud should have an allen - you may be able to just take it out .

Porsche went to the allen head bolts mentioned above. I've switched all of our cars to the m6x30 bolts. And i keep an extra set in the tool kit. Last thing you need is to drop a bolt or nut if you are changing the belts on the road and not have a spare and no way to fish it out.

Anyway- pull the fan and check the back side of the stud...

 

Thanks for the info. No need to take the fan out. After taking off the rear pulley, I had enough stud exposed to grab with a vice grips. Soaked it with Silli-Kroil, and it came right out. Going to pick up some extra studs.

 

Great work! I don't know if it's the right thing to do but I just got my bolts from the local hardware shop!

 

If you have any threads at all another method is to screw a nut on the stud and put a weld in it. It gives you more to wrench on, and the heat helps. FWIW, the best penetrating solution you can use is 1 part acetone to 1 part ATF.